Poles are mainly subjected to two kinds of stress. The first of these follows the direction of the row and is caused by the machines, while the second is lateral and is caused by winds.

In order to facilitate access for the machines, it is preferable to select poles that are narrow in the direction of the row. The limited area of "shadow" on either side of the pole will optimize all mechanical interventions.

Sides that are wide and flat will offer better resistance to the lateral stress that is mostly caused by the wind.

Please note that large U-shaped poles have different levels of resistance to bending, depending on the direction of stress.